Soybean Insects

Green Cloverworm, Plathypena scabra.

Adult moth.

Green cloverworm larva feeding.

Soybean plants defoliated by green cloverworms.

Green cloverworm larvae are light green with three pairs of white stripes running the length of the body. In addition to the three pairs of legs near the head, three pairs of fleshy 'prolegs' occur near the middle of the body, and one additional pair occurs on the last abdominal segment. Larvae thrash vigorously when disturbed. Smaller stages may drop from the leaf when disturbed and hang from a silken thread. Larvae chew irregularly shaped holes in the leaves from July through September.

To determine if treatment is justified, sample a minimum of 10 locations in the field. Use a cloth and bend over one rowfoot of soybeans on either side, shaking insects onto the cloth. Then calculate the average number of larvae per row-foot. Refer to Table 1 to find what response, if any, is necessary. Note that treatment thresholds vary with stage of soybean development, density of larval population, control costs, and expected soybean market value. This is an easy insect to kill, with most insecticides listing green cloverworm on the label.

Please refer to the most recent version of the Soybean Insect Management Guide for control options.

Page last updated 11/01/2013 by J.P. Michaud.